THE HEAD AND NECK "77 



the side of the root of the nose, the lachrymal sac, and the caruncula 

 lacrimalis. 



The external terminal branch of the nasal nerve emerges betvi'^een 

 the lower border of the nasal bone and the upper lateral nasal 

 cartilage, and descends beneath the compressor naris muscle to 

 the tip of the nose. Its twigs supply the skin of the tip, and lower 

 part of the side, of the nose. 



The infra-orbital nerve is the terminal part of the superior maxil- 

 lary division of the fifth. It emerges from the infra-orbital canal 

 through the infra-orbital foramen, where it is under cover of the 

 levator labii superioris. In this situation it communicates with the 

 infra-orbital branches of the facial, forming the infra-orbital plexus, 

 and it divides into three sets of branches, namely, inferior palpebral, 

 lateral nasal, and superior labial. The inferior palpebral branches 

 ascend to supply the skin and conjunctiva of the lower eyelid. The 

 nasal branches pass inwards, and are distributed to the skin of the 

 side of the nose. The superior labial branches, long and large, 

 descend to supply the skin and mucous membrane of one half of 

 the upper lip. As they descend they furnish twigs to the skin 

 between the infra-orbitaJ foramen and the upper lip. 



The temporal branch of the orbital or temporo-malar nerve is of 

 small size. Having traversed the temporal canal in the malar bone, 

 it pierces the temporal fascia about i inch above the front part of 

 the zygoma, and behind the marginal process on the postero-superior 

 or temporal border of the malar bone, and is distributed to a limited 

 portion of the skin over the anterior part of the temporal region. 



The malar branch of the orbital or temporo-malar nerve is of 

 small size, and emerges from the malar canal in the malar bone 

 through the malar foramen. It is distributed to the skin over the 

 malar bone. 



The long buccal nerve is a branch of the anterior division of the 

 inferior maxillary nerve. It emerges from beneath the anterior 

 border of the masseter on to the superficial surface of the buccinator, 

 where it divides into branches which communicate freely with the 

 buccal branches of the facial nerve, forming the buccal plexus. 

 Its final distribution is to the skin and mucous membrane of the 

 cheek, the branches to the latter piercing the buccinator. 



The auriculo-temporal nerve, which is a branch of the posterior 

 division of the inferior maxillary nerve, has been already described 

 as regards its cutaneous distribution (see p. 1070). 



The mental nerve is one of the terminal branches of the inferior 

 dental, which, in turn, is a branch of the posterior division of the 

 inferior maxillary nerv^e. It emerges from the dental canal in the 

 inferior maxilla through the mental foramen, under cover of the 

 depressor anguli oris, and in line with the interval between the two 

 lower bicuspid alveoli. Its branches supply the skin and mucous 

 membrane of one half of the lower lip, and the skin over one half of 

 the body of the inferior maxilla. 



The supra-orbital, infra-orbital, and mental nerves, being fre- 



